With an increasing emphasis on energy efficiency, attic insulation has often been supplemented by blown, loose-fill insulation, or by additional or thicker insulation batts to prevent heat loss in the winter and cool air loss in the summer. Unfortunately, thicker attic insulation can lead to poor air circulation when the spaces between the roof joists and the top wall plate of the building are closed or obstructed. These spaces must be left open to provide air flow between the soffit area and the attic space, for reducing excess humidity, condensation and heat, which have been known to deteriorate roofing and structural components.
Ventilation can also help reduce the roof deck temperature to prevent damage to the roof deck and roofing shingles that can result from excessive heat in the summer and ice dam leaks in the winter. Roof ventilation is required by most building codes and by shingle manufacturers to validate warranties.
Venting moisture from the ceiling cavity is particularly a problem in cathedral ceilings, where moisture can migrate into the ceiling cavity from the open living area, especially when there is no vapor barrier installed on the interior side of the ceiling. In order to keep cathedral and non-cathedral ceiling cavities open, and thereby provide a channel for air flow, baffled vents have been installed to promote ventilation. Vented cathedral ceilings are often built in a time consuming two-step application process. The installer first places baffle vents or air chutes from the eaves of the ceiling to the ridge and then staples the baffles or air chutes to the roof sheathing between the roof rafters. The vent or chute creates a maintainable channel for ventilating air and entrained moisture. Batt insulation is then installed inwardly and adjacent to the baffle vent.
There is a need, therefore, for an improved insulation product that reduces installation complexity. Still further, there is a need for an insulation product that promotes improved ventilation.